<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>7.3</title>
	<script src="js/vue.js"></script>
	<style>
		.active{ text-decoration: underline;}
		.text-danger {front-weight: bold;}
		</style>
	</head>
	<body>
		<div id="app">
			<div v-bind:class="[isActive? 'active':",'text-danger']">Hello School!</div>
		</div>
	</body>
	var vm = new Vue({
		el: '#app',
		data: {
			isActive: true
		}
	})
</html>